added unit test for max-route
added unit test for max-route

arifogel/batfish,batfish/batfish,dhalperi/batfish,intentionet/batfish,intentionet/batfish,intentionet/batfish,batfish/batfish,intentionet/batfish,arifogel/batfish,dhalperi/batfish,batfish/batfish,dhalperi/batfish,intentionet/batfish,arifogel/batfish